1. Field of the Invention
The present invention relates to a triple conveyor and more particularly, to a conveyor including a chain gear, a coaxial roller, and end wheels of a coaxle which can transport products quickly and accurately, and reduce the noise and vibration of the conveyor so as to allow for the use of robots in place of manpower in the factory.
2. Description of the Prior Art
In a conventional conveyor, a plurality of spaced rollers are fixed to a chain which moves forward on an endless track. Accordingly, the rollers move forward together with the chain to transport each pallet on which a product is loaded. Such a transport mechanism makes a large noise due to friction among drive members, and vibration between the pallet and the rollers. Therefore, the vibration causes many problems in operations using robots in place of manpower. Moreover, such a noise annoys a worker and deteriorates the working environment.
Another conventional conveyor which includes a roller which does not move forward with the chain. The roller just revolves at a stationary position to reduce noise and vibration. However, since the roller is formed integrally with the sprocket, revolution speed of the roller is constant and cannot be promptly adjusted according to the transport conditions. Therefore products cannot be moved quickly to increase the production efficiency.
According to the U.S. patent application, Ser. No. 07/290,255 entitled "Power Free Triple Conveyor" owned by the inventor of the present application, a conveyor is disclosed which includes a sprocket mounted on the each shaft through a bearing, a roller separately formed and freely rotated on the sprocket and having a plurality holes, a plurality of springs resiliently installed within the holes of the roller, a pair of friction plates and snap rings located adjacent to the roller, and a guide rail fixed at the upper portion of the frame. The plurality of springs resiliently installed within the holes suffer from some problems. For example, it is difficult to meet the requirement of having all the springs within the holes of the roller exhibiting equal resilient force, to replace old springs with new springs, and for the springs to maintain their original form when the roller slips from the friction plate.
In order to eliminate the disadvantages mentioned above, according to the present invention, the conveyor includes a chain gear, a coaxial roller having a plurality of longitudinal slots, and fixed end wheels of a coaxle for slidably, rotatably engaging with receiving grooves disposed in a frame.